Gene Roddenberry was a Starfleet flag officer during the 23rd century.
Roddenberry was listed as the commander in chief on the dedication plaques of the USS Shenzhou, the USS Discovery, and the USS Enterprise. (DIS: "The Vulcan Hello", dedication plaque; DIS: "Context Is for Kings", dedication plaque; DIS: "Such Sweet Sorrow"; SNW: "Strange New Worlds")
In 2259, Admiral Robert April went to Roddenberry himself to get read in on what happened on the USS Discovery. (SNW: "Strange New Worlds")
In 2293, he was listed as a Starfleet Command officer on the dedication plaque of the USS Enterprise-B. (Star Trek Generations, dedication plaque)
This character was only mentioned in writing.
This officer was named after Star Trek creator Gene Roddenberry.